# Update State Variables Automatically
AlpineJS has a global state management system through its global variable named [store](https://alpinejs.dev/globals/alpine-store).
We can store a variable named `total` for a page loaded in the browser like this :
```javascript
document.addEventListener('alpine:init', () =>
{
Alpine.store('global_data',
{
total: 0,
});
});
```
(Note: This is **not** `localStorage`, so the store variable will be reset once you navigate to another page)
If you're looking to assign and update a variable stored in `$store` with change in input elements' values, you don't need to attach event listeners to the respective input elements at all.
Let's have 2 input elements, one for the **quantity** (text field) and one for the **size** of the product (select), where each of the 3 sizes has pre-defined prices.
So for the quantity we can bind the value of the input to a local AlpineJS variable like `` and a `